If an rf source is applied at the A end of the length of wire from A
to B, the wave will travel along the wire until it reaches the B end.
Since the B end is free, an open circuit exists and the wave cannot
travel . This is a point of high impedance. Then the wave back
(reflects) from this point of high impedance and travels toward the
starting point, where it is again reflected. The energy of the wave
would be gradually dissipated by the resistance of the wire of this
back-and-forth motion (oscillation);


rf source A .____wire____.B


So how rf leave the antenna ???!!!!!!

in practical we use this configration :


---------- Antenna
rf source (transmmiter) ----|
---------- dummy load

Thanks